Block.



A. -B. TA RBOX. BLOCK. APPLIOATION FILED JUNE 24, 1905.

PATENTED MAY 29, 1909.

ALFRED B. TARBOX, OF BOSTON, MASSACHUSETTS.

Specification of Letters latent.

BLOCK.

Patented May 22, 1906.

Application filed June 24, 1905- elial O- 2661755.

To all whom, it may concern.-

Be it known that I, ALFRED B. TARBOX, of Boston, in the county ofSuffolk and State of Massachusetts, a citizenof the United States, haveinvented a new and useful Improvement in Blocks, of which the followingis a full, clear, and exact description, reference being had to theaccompanying drawings, forming a part of this specification, inexplaining its nature.

The special object of my invention is to make a light strong block ofsimple structure and which can be manufactured at little cost. Theseobjects I attain by making the cheeks of the block and the plate orplates interposed between the sheaves, if there be more than one, out ofthin sheet-metal plate stamped or died out in proper form. I-Ieretoforeit has been thought insufficient to make these parts, especially thecheeks of the block, out of a single thickness of sheet-metal plate. Ihave found, however, that by properly combining and otherwisereinforcing the cheeks this may be done and they be strong enough towithstand the rough usage to which a block is ordinarily subjected.

My invention can best be seen and understood by reference to thedrawings, in which Figure 1 represents the new form of block in sideelevation. Fig. 2 shows the block in front elevation. Fig. 3 shows avertical section of the block. Fig. 4 shows in front elevation a blockcontaining more than one sheave.

Referring to the drawings, I will describe my invention as applied tothe construction of a single sheave-block, as shown in Figs. 1 to 3,inclusive.

A A represent the respective cheeks of the block,whicli aremade each ofa single thickness of sheet-1netal plate. The cheeks are spaced apart byseparators B to allow for the insertion of the sheave C, which turnsupon the usual sheave-pin C. This sheave-pinpasses through the twocheeks and also through the arms of a strap D, carrying the hook D, thearms of the strap being drawn down over the ends of the cheeks, so thatthey will extend down outside and alongside the same and be secured tothe sheave-pin, as before described. To prevent the sheave-pin fromturning, it may be provided near its head with a key 0, which fits intoa slight hole or recess d, formed in the arm of the strap-bar throughwhich it passes With respect now to the mode of strengthening the checksto stand the strain to which they are subjected it is to be noted in thefirst place that the cheeks are riveted fast to the separators B,interposed between them. These separators are interposed, preferably,two at the top and one at the bottom end of the cheeks, and the cheeksare united directly to them and to one another by rivets B, which arepassed through the cheeks and separators (they being made tubular inform) and then headed. The single thickness of sheet-metal plate is thusbound tight against the ends of the separators, which give adesirableinflexibility to the metal cheeks and very materially strengthen them.

For further strengthening the cheeks each is provided along its outeredge or periphery with an outwardly bent or turned rim a, which at thepoint a, where the arms of the strap-bar turn around the edge of thecheeks, is cut away to admit of the arms passing down alongside thesame, as before described. This turned edge or rim not only acts as areinforcement preventing the thin metal bending, but it also acts as aguard to prevent the fraying or wearing out of the rope in the operationof the block.

The cheeks are also reinforced or strengthened by the thin metal beingbent or pressed outwardly and inwardlyoutwardly by the annular portion aand inwardly at the center by the portion (1 This inwardly pressedcenter portion by contacting with the hub of the sheave acts as a guardto prevent it from interfering with or wearing against the cheek whenturning, and the annular outwardlypressed portion a forms on the insidean annular edge a which acts as a guard adjacent to the periphery of thesheave for preventing the rope becoming displaced from it.

In Fig. 4 I have represented a block containing two sheaves, which issubstantially the same structure as before described, with the exceptionthat a flat thin sheet-metal plate substantially oval in shape isinterposed between the sheaves. The separators B are interposed betweenthe respective cheeks and adjacent sides of this plate and the wholefastened together by rivets B passing through the cheeks, separators,and interposed plate, then headed in the manner before described. v

Having thus fully described my invention,

I claim and desire to secure by Letters Patent of the United States-I 1. A block of the character specified having cheeks of a singlethickness of sheetmetal plate, separators for said cheeks to which theyareriveted at the top and bottom, said cheeks also being turned or bentoutwardly along the'edge or periphery thereof, a sheave interposedbetween said cheeks, a sheave-pin and a strap the arms of which areturned to extend down alongside said checks on the outside thereof andbe secured to said sheavein substantially as described.

2. A block of the character specified having cheeks of a singlethickness of sheetmetal plate, separators for said cheek to which saidcheeks are riveted at the top and bottom by rivets extending through thesame, said cheeks being turned or bent outwardly along their edges orperipheries and having also outwardly and inwardly bent portions a and aa sheave interposed between said cheeks, a sheave-pin, and a strap thearms of which are turned to extend down alongside said cheeks on theoutside thereof and be secured to said sheave-pin substan tially asdescribed.

3. A block of the character specified having checks of a singlethickness of sheetmetal plate, two or more sheaves interposed betweenthe same, a fiat sheet-metal plate or plates substantially oval in shapebetween said sheaves, separators between said cheeks and plate or platesto which said cheeks are riveted at the top and bottom by rivetsextending through said cheeks, separators and plates and headed on theoutside of said cheeks, said cheeks also being turned or bent outwardlyalong the edges or peripheries there of, a sheave-pin for supportingsaid sheave, and a strap the arms of which are turned to extend downalongside said cheeks on the outside thereof and be secured to saidsheave-pin substantially as described.

ALFRED B. TARBOX.

Witnesses:

JOHN E. R. HAYES, ROBERT E. BREWER.

